Deck 21: The Generation of Biochemical Energy

Question 1

Which of the following organelles is involved in the synthesis of macromolecules?

A)Golgi apparatus
B)lysosome
C)rough endoplasmic reticulum
D)mitochondria
E)smooth endoplasmic reticulum

Answer 1

Golgi apparatus

Question 2

All of the following are specific requirements for energy in biochemical processes except

A)stored energy must be in a form that is chemically accessible.
B)release of energy from storage must occur at a carefully controlled rate.
C)release of energy from food must occur gradually.
D)energy needed for unfavorable reactions must be available in the form of heat.
E)the correct amount of heat must be released from biochemical reactions to maintain body temperature.

Answer 2

energy needed for unfavorable reactions must be available in the form of heat.

Question 3

The regions of a cell found between the nuclear membrane and the cell membrane is called the

A)cytosol.
B)mitochondria.
C)mitochondrial matrix.
D)organelles.
E)cytoplasm.

Answer 3

cytoplasm.

Question 4

Exergonic reactions are those that have a ________ value of ΔG and ________ spontaneous.

A)positive;are
B)positive;are not
C)negative;are
D)negative;are not
E)none of the above

Question 5

Endergonic reactions are those that are ________ and that ________ liberate free energy.

A)spontaneous;do
B)nonspontaneous;do
C)spontaneous;do not
D)nonspontaneous;do not
E)none of the above

Question 6

Endergonic reactions are those that have a ________ value of ΔG and ________ spontaneous.

A)positive;are
B)positive;are not
C)negative;are
D)negative;are not
E)none of the above

Question 7

The biochemical process in which complex molecules are broken down into simpler ones and energy is released is referred to as

A)anabolism.
B)catabolism.
C)digestion.
D)metabolism.
E)respiration.

Question 8

Exergonic reactions are those that are ________ and that ________ liberate free energy.

A)spontaneous;do
B)nonspontaneous;do
C)spontaneous;do not
D)nonspontaneous;do not
E)none of the above

Question 9

Photosynthesis is an ________ process because the free energy of the products is ________ the free energy of the reactants.

A)endergonic;greater than
B)exergonic;greater than
C)endergonic;less than
D)exergonic;less than
E)equilibrium;the same as

Question 10

The mitochondria are the organelles where ________ takes place and most ________ is produced.

A)citric acid cycle;ATP
B)catabolism;acetyl coenzyme A
C)catabolism;ATP
D)citric acid cycle;acetyl coenzyme A
E)catabolism;fatty acid

Question 11

Which of the following organelles is involved in protein synthesis and transport?

A)Golgi apparatus
B)lysosome
C)rough endoplasmic reticulum
D)mitochondria
E)smooth endoplasmic reticulum

Question 12

The cellular organelle associated with energy production is the

A)nucleus.
B)mitochondrion.
C)Golgi apparatus.
D)endoplasmic reticulum.
E)lysosome.

Question 13

Metabolism is composed of which process(es)?

A)anabolism
B)catabolism
C)oncologism
D)both A and B
E)both B and C

Question 14

Which of the following organelles is involved in breakdown of unwanted molecules and cellular components?

A)Golgi apparatus
B)lysosome
C)rough endoplasmic reticulum
D)mitochondria
E)smooth endoplasmic reticulum

Question 15

The process by which the cell produces ATP in the mitochondria is called

A)oxidative phosphorylation.
B)hydrolysis.
C)substrate-level phosphorylation.
D)electron transport.

Question 16

The cellular organelle that is responsible for most cellular catabolic redox reactions is the

A) mitochondrion.
B)chloroplast.
C)peroxisome.
D)ribosome.

Question 17

The sum of all the biochemical reactions occurring in an organism is

A)anabolism.
B)catabolism.
C)digestion.
D)metabolism.
E)respiration.

Question 18

The ultimate source of energy for all but a very few biochemical reactions is

A)hydrocarbons.
B)carbohydrates.
C)lipids.
D)the sun.
E)ATP.

Question 19

A metabolic pathway that can be illustrated as A → B → C → D is said to be a(an)________ pathway.

A)anabolic
B)catabolic
C)cyclic
D)linear
E)spiral

Question 20

The enzymes of the oxidative phosphorylation system are located in the

A)cytosol.
B)nucleus.
C)matrix of the mitochondria.
D)cristae of the mitochondria.
E)endoplasmic reticulum.

Question 21

All of the following chemicals except ________ provide protection against potentially harmful oxygen species.

A)beta-carotene
B)catalase
C)hydrogen peroxide
D)vitamin C
E)vitamin E

Question 22

A cyclic metabolic sequence can best be described as one in which

A)the product of the first reaction is the starting material for the next reaction,and so on.
B)a series of reactions regenerates the initial reactant.
C)the various reactions have virtually no connection to one another.
D)the same set of enzymes progressively builds up a molecule.
E)the same set of enzymes catalyses the same reaction in both the forward and reverse directions.

Question 23

Harmful byproducts of biochemical oxidation include

A)superoxide dismutase and catalase.
B)vitamins A,C,and E.
C)superoxide ions and hydroxyl free radicals.
D)ATP.
E)coenzyme Q.

Question 24

The abbreviation ATP stands for

A)adenine + three phosphates.
B)adenosine triphosphate.
C)adenosine tetraphosphate.
D)anabolic triple phosphate.
E)alanine triphosphate.

Question 25

Which of the following reactions is the least energetic?

A)ATP + H₂O → ADP + P_i
B)ATP + H₂O → AMP + PP_i
C)ADP + H₂O → AMP + P_i
D)AMP + H₂O → Adenosine + P_i
E)All give off the same amount of energy.

Question 26

The synthesis of ATP from ADP and monohydrogen phosphate ________ 7 kcal/mol of energy and is an ________ reaction.

A)releases;endergonic
B)consumes;exergonic
C)releases;exergonic
D)consumes;endergonic
E)None of these are correct.

Question 27

All of the following are energy strategies used in biochemical reactions except

A)ATP is produced as a means of transferring energy.
B)exergonic reactions are used to drive unfavorable reactions.
C)chemical reactions occur in pairs in order to change the value of ΔG for one of the reactions.
D)coenzymes which can exist in oxidized or reduced forms are used to transfer electrons.
E)ADP is transformed into a higher energy molecule when coupled to an exergonic reaction.

Question 28

The common molecule produced from all foods at the second stage of catabolism is

A)ADP.
B)acetyl-CoA.
C)glucose.
D)citric acid.
E)carbon dioxide.

Question 29

The reaction in which ATP is converted to ADP with release of 7.3 kcal is a(an)________ reaction.

A)hydrolysis
B)reduction
C)combustion
D)oxidation
E)polymerization

Question 30

The biochemical process in which simple molecules are combined to make larger ones and energy is consumed is referred to as

A)anabolism.
B)catabolism.
C)digestion.
D)metabolism.
E)respiration.

Question 31

Which of the following statements about free radicals is incorrect?

A)They are a by-product of oxygen-consuming redox reactions.
B)Their unpaired electron makes them extremely reactive.
C)They can disrupt covalent bonds in biomolecules.
D)B vitamins provide protection from their harmful effects.
E)Superoxide catalase is one of the specific enzymes that can provide protection from their harmful effects.

Question 32

The hydrolysis of ATP to ADP ________ 7 kcal/mol of energy and is an ________ reaction.

A)releases;endergonic
B)consumes;exergonic
C)releases;exergonic
D)consumes;endergonic
E)None of these are correct.

Question 33

The purpose of coupling two biochemical reactions is to

A)lower the activation energies of both reactions.
B)convert an endergonic reaction to an exergonic one.
C)convert an exergonic reaction to an endergonic one.
D)use an endergonic reaction to drive an exergonic reaction.
E)use an exergonic reaction to drive an endergonic reaction.

Question 34

A metabolic pathway in which a molecule is progressively built up by repeated interaction with the same set of enzymes is a(an)________ pathway.

A)anabolic
B)catabolic
C)cyclic
D)linear
E)spiral

Question 35

In a pair of coupled reactions,if the favorable reaction releases more energy than the amount required by the unfavorable reaction,the excess energy is

A)reabsorbed by the favorable reaction to be used later.
B)released as heat and used to maintain body temperature.
C)used by the unfavorable reaction to create more products than normally expected.
D)converted to high energy ATP.
E)used to produce reduced coenzymes.

Question 36

List and discuss the reasons that ATP is so useful as a biochemical energy transport molecule.

Question 37

ATP is the molecule most often used for energy transport because

A)a relatively large amount of energy is released upon hydrolysis of its two phosphoric anhydride bonds.
B)its hydrolysis releases an intermediate amount of energy and is relatively slow except in the presence of the appropriate enzymes.
C)it can only be produced in the citric acid cycle.
D)it can only be produced as a result of reactions in the electron transport chain.
E)its production from ADP is endergonic.

Question 38

Which sequence illustrates the order of the steps from food to biochemically useful energy?

A)digestion;citric acid cycle;ATP production;acetyl-CoA production
B)digestion;citric acid cycle;acetyl-CoA production;ATP production
C)citric acid cycle;digestion;acetyl-CoA production;ATP production
D)digestion;acetyl-CoA production;citric acid cycle;ATP production
E)digestion;acetyl-CoA production;ATP production;citric acid cycle

Question 39

A metabolic pathway in which a series of steps,each using different enzymes,regenerates one of the early reactants,is a(an)________ pathway.

A)anabolic
B)catabolic
C)cyclic
D)linear
E)spiral

Question 40

A spiral metabolic sequence can best be described as one in which

A)the product of the first reaction is the starting material for the next reaction,and so on.
B)a series of reactions regenerates the initial reactant.
C)the various reactions have virtually no connection to one another.
D)the same set of enzymes progressively builds up or breaks down a molecule.
E)the same set of enzymes catalyses the same reaction in both the forward and reverse directions.

Question 41

Which of the following does not undergo oxidation-reduction reactions?

A)ATP
B)NADH
C)NADPH
D)FAD

Question 42

Which statement concerning coenzymes and redox reactions is incorrect?

A)Oxidation can be considered as loss of hydrogen or gain of oxygen.
B)Reduction can be considered as gain of hydrogen or loss of oxygen.
C)NAD⁺ is the oxidized form of NADH.
D)An oxidation reaction cannot occur unless a reduction reaction also occurs.
E)FAD is the reduced form of FADH₂.

Question 43

All of the following chemicals are involved in the citric acid cycle except

A)acetyl-CoA.
B)isocitrate.
C)succinate.
D)malate.
E)ascorbate.

Question 44

In the first step of the citric acid cycle,acetyl-CoA reacts with ________ to produce ________,which is isomerized to ________ in the second step.

A)succinate;fumarate;malate
B)succinate;malate;fumarate
C)oxaloacetate;isocitrate;citrate
D)oxaloacetate;citrate;isocitrate
E)aconitase;isocitrate;citrate

Question 45

Which group of compounds includes only low-energy molecules?

A)ATP;acetyl-CoA;NADH;FADH₂
B)ADP;acetyl-CoA;NAD⁺;FAD
C)ATP;CO₂;NADH;FADH₂
D)ADP;CO₂;NADH;FADH₂
E)ADP;CO₂;NAD⁺;FAD

Question 46

In addition to producing ATP,the citric acid cycle produces ________ as high energy molecules and ________ as its major chemical waste product.

A)oxidized coenzymes;H₂O
B)oxidized coenzymes;CO₂
C)reduced coenzymes;H₂O
D)reduced coenzymes;CO₂
E)ADP;O₂

Question 47

Which group of compounds includes only high-energy molecules?

A)ATP;acetyl-CoA;NADH;FADH₂
B)ADP;acetyl-CoA;NAD⁺;FAD
C)ATP;CO₂;NADH;FADH₂
D)ADP;CO₂;NADH;FADH₂
E)ATP;CO₂;NAD⁺;FAD

Question 48

The formation of acetyl coenzyme A is an example of a(an)________ reaction.

A)esterification
B)redox
C)addition
D)acid/base
E)elimination

Question 49

Which of the following is not true of NAD⁺ and FAD?

A)These molecules when present in the reduced state are used to produce ATP.
B)They both contain two nucleosides.
C)They donate electrons to the electron transport system.
D)The reduced form of FAD has more energy than the reduced form of NAD⁺.

Question 50

In many catabolic processes the principal product is ________ to be processed in the ________.

A)acetyl coenzyme A;citric acid cycle
B)acetyl coenzyme A;electron transport chain
C)ATP;electron transport chain
D)ATP;citric acid cycle
E)ADP;electron transport chain

Question 51

In steps 3 and 4 of the citric acid cycle,successive oxidations produce ________ as a waste product and the four-carbon carrier ________.

A)CO₂;oxaloacetate
B)ADP;oxaloacetate
C)CO₂;succinyl-CoA
D)ADP;succinyl-CoA
E)CO₂;malate

Question 52

Which of the following cofactors is used in fatty acid synthesis?

A)NADH
B)FAD
C)NADPH
D)FADH₂
E)NAD⁺

Question 53

Which statement is true concerning the relationship between FAD and FADH₂?

A)FADH₂ is the oxidized form of FAD.
B)FADH₂ is the reduced form of FAD.
C)The conversion of FADH₂ to FAD is an acid/base reaction.
D)The conversion of FADH₂ to FAD is a cyclization reaction.
E)none of the above

Question 54

Which of the following is common to the structures of NAD⁺,and FAD?

A)nicotinic acid
B)nicotinamide
C)ATP
D)ADP
E)AMP

Question 55

In steps 5-8 of the citric acid cycle,the high-energy molecules ________,________,and ________ are produced,and ________ is regenerated to begin another turn of the cycle.

A)GDP;FADH₂;NADH/H⁺;oxaloacetate
B)GTP;FADH₂;NADH/H⁺;oxaloacetate
C)ATP;FADH₂;NADH/H⁺;citrate
D)ADP;FAD;NAD⁺;oxaloacetate
E)GDP;FADH₂;NADH/H⁺;isocitrate

Question 56

Which reaction of the citric acid cycle involves the addition of water across the double bond?

A)conversion of isocitrate to α-ketoglutarate
B)conversion of succinate to fumarate
C)conversion of malate to oxaloacetate
D)conversion of fumarate to malate
E)conversion of citrate to isocitrate

Question 57

The hydrolysis of creatine phosphate is coupled with the synthesis of ATP.The equations for the reactions are given below.Would this coupling be favored?
Creatine phosphate + H₂O → Creatine + HOPO₃^-2 ΔG = -10.3 kcal/mol
ADP + HOPO₃^-2 + H⁺ → ATP + H₂O ΔG = +7.3 kcal/mol

Question 58

Which statement is true concerning the relationship between NAD⁺ and NADH?

A)NAD⁺ is the oxidized form of NADH.
B)NAD⁺ is the reduced form of NADH.
C)The conversion of NAD⁺ to NADH is an acid/base reaction.
D)The conversion of NAD⁺ to NADH is a cyclization reaction.
E)none of the above

Question 59

Which of the following reactions of the citric acid cycle is a decarboxylation occurring?

A)conversion of succinyl CoA to sucicinyl
B)conversion of isocitrate to α-ketoglutarate
C)α-ketoglutarate to succinyl CoA
D)All three reactions are decarboxylations.
E)only B and C

Question 60

Every turn of the citric acid cycle directly produces ________ high energy molecule(s).

A)zero
B)one
C)two
D)three
E)six

Question 61

Which reaction of the citric acid cycle generates the high energy molecule GTP?

A)citrate to isocitrate
B)isocitrate to α-ketoglutarate
C)α-ketoglutarate to succinyl CoA
D)succinyl CoA to succinate
E)succinate to fumarate

Question 62

Match the following.
acetyl-CoA

A)the molecule produced from digestion products in the second stage of catabolism
B)metabolic processes that consume energy in order to build molecules
C)the stage of catabolism in which acetyl-CoA is oxidized to produce ATP,reduced coenzymes,and CO₂
D)metabolic processes that break down large molecules,thereby releasing energy
E)the universal energy currency of the cell;a molecule used to transfer energy
F)a molecule that can be phosphorylated as a means of temporarily storing energy
G)the stage of catabolism in which complex food molecules are broken down into simpler substances for transport and/or further reaction
H)the stage of catabolism in which the energy stored in reduced coenzymes is converted to ATP

Question 63

Match the following.
digestion

A)the molecule produced from digestion products in the second stage of catabolism
B)metabolic processes that consume energy in order to build molecules
C)the stage of catabolism in which acetyl-CoA is oxidized to produce ATP,reduced coenzymes,and CO₂
D)metabolic processes that break down large molecules,thereby releasing energy
E)the universal energy currency of the cell;a molecule used to transfer energy
F)a molecule that can be phosphorylated as a means of temporarily storing energy
G)the stage of catabolism in which complex food molecules are broken down into simpler substances for transport and/or further reaction
H)the stage of catabolism in which the energy stored in reduced coenzymes is converted to ATP

Question 64

Match the following.
electron transport chain

A)the molecule produced from digestion products in the second stage of catabolism
B)metabolic processes that consume energy in order to build molecules
C)the stage of catabolism in which acetyl-CoA is oxidized to produce ATP,reduced coenzymes,and CO₂
D)metabolic processes that break down large molecules,thereby releasing energy
E)the universal energy currency of the cell;a molecule used to transfer energy
F)a molecule that can be phosphorylated as a means of temporarily storing energy
G)the stage of catabolism in which complex food molecules are broken down into simpler substances for transport and/or further reaction
H)the stage of catabolism in which the energy stored in reduced coenzymes is converted to ATP

Question 65

The proton-translocating ATP synthase complex is located in the

A)cytosol.
B)outer membrane of the mitochondria.
C)inner membrane of the mitochondria.
D)matrix.
E)intermembrane space.

Question 66

How many ATP molecules are formed for each NADH molecule brought into complex I?

A)1
B)2
C)3
D)4
E)5

Question 67

Which of the following are electron carriers in the electron transport chain?

A)Fe-S clusters
B)Coenzyme Q
C)Cytochrome C
D)Iron(II)ions
E)all of these

Question 68

The driving force which provides the energy for synthesis of ATP in the fourth stage of metabolism is the

A)exergonic conversion of ADP to ATP.
B)energy difference between reduced carbon atoms and oxidized carbon atoms.
C)concentration gradient of hydrogen ions between the two sides of the inner mitochondrial membrane.
D)concentration difference in oxygen between the cell and the intercellular fluid.
E)none of the above

Question 69

The fourth stage of metabolism,in which the high energy molecules from stage three are oxidized to produce ATP is referred to as

A)active transport.
B)reductive phosphorylation.
C)the electron transport chain.
D)the Krebs cycle.
E)glycolysis.

Question 70

Match the following.
catabolism

A)the molecule produced from digestion products in the second stage of catabolism
B)metabolic processes that consume energy in order to build molecules
C)the stage of catabolism in which acetyl-CoA is oxidized to produce ATP,reduced coenzymes,and CO₂
D)metabolic processes that break down large molecules,thereby releasing energy
E)the universal energy currency of the cell;a molecule used to transfer energy
F)a molecule that can be phosphorylated as a means of temporarily storing energy
G)the stage of catabolism in which complex food molecules are broken down into simpler substances for transport and/or further reaction
H)the stage of catabolism in which the energy stored in reduced coenzymes is converted to ATP

Question 71

The electrons brought into the electron transport chain are transferred in the following order of

A)complex I;CoQ;complex III;cytochrome c;complex IV.
B)complex I;complex III;CoQ;cytochrome c;complex IV.
C)CoQ;cytochrome c;complex IV,complex I;complex III.
D)complex I;complex III;cytochrome c;CoQ;complex IV.
E)cytochrome c;CoQ;complex I;complex III;complex IV.

Question 72

After O₂ has been reduced in the electron transport chain,the oxygen atoms are part of what molecules?

A)ATP
B)water
C)carbon dioxide
D)acetate
E)acetyl-CoA

Question 73

Match the following.
anabolism

A)the molecule produced from digestion products in the second stage of catabolism
B)metabolic processes that consume energy in order to build molecules
C)the stage of catabolism in which acetyl-CoA is oxidized to produce ATP,reduced coenzymes,and CO₂
D)metabolic processes that break down large molecules,thereby releasing energy
E)the universal energy currency of the cell;a molecule used to transfer energy
F)a molecule that can be phosphorylated as a means of temporarily storing energy
G)the stage of catabolism in which complex food molecules are broken down into simpler substances for transport and/or further reaction
H)the stage of catabolism in which the energy stored in reduced coenzymes is converted to ATP

Question 74

The metal that acts as an electron carrier in the cytochromes in the electron transport chain is

A)magnesium.
B)chromium.
C)iron.
D)cobalt.
E)hydrogen.

Question 75

How many ATP molecules are formed for each FADH₂ molecule brought into complex II?

A)1
B)2
C)3
D)4
E)5

Question 76

Match the following.
ADP

A)the molecule produced from digestion products in the second stage of catabolism
B)metabolic processes that consume energy in order to build molecules
C)the stage of catabolism in which acetyl-CoA is oxidized to produce ATP,reduced coenzymes,and CO₂
D)metabolic processes that break down large molecules,thereby releasing energy
E)the universal energy currency of the cell;a molecule used to transfer energy
F)a molecule that can be phosphorylated as a means of temporarily storing energy
G)the stage of catabolism in which complex food molecules are broken down into simpler substances for transport and/or further reaction
H)the stage of catabolism in which the energy stored in reduced coenzymes is converted to ATP

Question 77

All of the following molecules are directly involved in the electron transport chain except

A)coenzyme Q.
B)ADP.
C)cytochrome c.
D)acetyl-CoA.
E)H₂O.

Question 78

Match the following.
ATP

A)the molecule produced from digestion products in the second stage of catabolism
B)metabolic processes that consume energy in order to build molecules
C)the stage of catabolism in which acetyl-CoA is oxidized to produce ATP,reduced coenzymes,and CO₂
D)metabolic processes that break down large molecules,thereby releasing energy
E)the universal energy currency of the cell;a molecule used to transfer energy
F)a molecule that can be phosphorylated as a means of temporarily storing energy
G)the stage of catabolism in which complex food molecules are broken down into simpler substances for transport and/or further reaction
H)the stage of catabolism in which the energy stored in reduced coenzymes is converted to ATP

Question 79

The process of converting ADP to ATP in the mitochondrion takes place by a process known as

A)oxidative phosphorylation.
B)chemiosmosis.
C)respiration.
D)reductive phosphorylation.
E)chemiosmotic phosphorylation.

Question 80

Match the following.
citric acid cycle

A)the molecule produced from digestion products in the second stage of catabolism
B)metabolic processes that consume energy in order to build molecules
C)the stage of catabolism in which acetyl-CoA is oxidized to produce ATP,reduced coenzymes,and CO₂
D)metabolic processes that break down large molecules,thereby releasing energy
E)the universal energy currency of the cell;a molecule used to transfer energy
F)a molecule that can be phosphorylated as a means of temporarily storing energy
G)the stage of catabolism in which complex food molecules are broken down into simpler substances for transport and/or further reaction
H)the stage of catabolism in which the energy stored in reduced coenzymes is converted to ATP